Electrolytically formed tank



Dec. 3, 1935, BART ELECTROLYTICALLY FORMED TANK Filed Feb. 2, 193 2 sheets sh'eet 1 3 I lN-VENTOR sLAslqs 555 fi/mymu,

ATTORNEY '11, 'IIIIIIIIIIIIIIIIIIII 2 Sheets-Sheet 2 INVENTOR BLASIUS BART Dec. 3, 1935. B. BART ELECTROLYTICALLY FORMED TANK Filed Feb. 2, 1951 //////////////4 'III'IIIIIIIIIIIIIIIII/l/ Patented Dec. 3, 1 935 lTED STATES PATENT OFFICE ELECTROLYTICALLY FORMED TANK Blasius Bart, East Orange, N. J.

Application February 2, 1931, Serial No. 512,991 12 Claims. (o1. 2044;)

The invention relates to an improvement in receptacles, tubings, pressure-tanks and other hollow articles formed primarily of a shell of laminated electrolytically deposited layers of 5 different metals; to a method of manufacturing such articles and to an improvement in mold structures for use in practicing the method and forming the articles herein featured. The present disclosure constitutes an improvement and development of the invention disclosed in my cO-pending application entitled Improvements in high pressure tanks, Serial No. 512,990 filed February 2, 1931, (attorneys No; 3,772), and is a companion case to Serial No. 512,992 filed Feb- 'ruary 2, 1931, entitled Seamless tank" (attorneys No. 3,804)

In forming receptacles, tanks, and other shelllike hollow articles by electrolytic deposition of metals, it has been known to form the shell on molds which subsequently were melted, dissolved and otherwise reduced to a fluid condition so as to be poured from the article formed thereon. Such practice has numerous practical disadvantages; the molds can be used only once and are then destroyed in the operation of removing them; it is difiicult, if not practically impossible, to make replicas of the formed article and the usual melting and dissolving operations are very apt to disfigure or mar the surfaces of the formed article in contact with the mold. With some forms of articles so produced, it is extremelydifiicult to obtain the electrolytic deposition in a homogeneous layer of uniform thickv ness throughout the formed article and this is particularly true of those portions which form or contain re-entrant angles, recesses and the like, with the result that there is formed weakened areas in the structure. These weakened areas are not always apparent on inspection, as it is difiicult to detect where a coating may be thin. There is the possibility that tanks and like closed receptacles intended to contain high internal pressures, are apt to rupture in the areas of such thin deposits.

The primary object of the invention is to provide a hollow article of the type outlined, which can be formed economically; which can be formed with any desired structural strength; in which the interior or other surface engaging the mold will retain its original finish and in general which will provide an inexpensive, rugged article having a pleasing artistic appearance.

Another object of the invention is to provide an improved method by means of which articles receiving surface from time to time as it be- 10 comes worn in use.

The invention also features a fabricated construction of deposit receiving mold, formed of a plurality of readily assembled and demountable parts, some of which are designed to be re- 15 moved intact from the finished article, and other parts of which are designed to constitute part of the finished article and are secured thereto by the electrolytic soldering of the deposited layers.

Various other objects and advantages of the 20 invention will be in part obvious from a consideration of-the. method features of the disclosure and from an inspection of the accompanying drawings and'in part will be more fully set forth in the following particular description 25 of one method of practicing the invention, and the invention also consists in certain new and novel modifications of the preferred method and other features of construction and combinations Y of parts hereinafter set forth and claimed. 30

In the accompanying drawings? Fig. 1 is a View in axial section of a mold apparatus with a shell forming part of the finished article in position thereon and illustrating the assemblage constituting the initial step 35 in the method of manufacturing the completed article;

Fig. 2 is a view similar to Fig. l with parts of the mold removed and showing the second step of the method at the start of the operation where 40 the shell is stripped from the major portion of the mold;

I Fig. 3 is an axial sectional view of the shell removed from the mold parts and showing the preformed bottom member about to be inserted 45 in place, constituting the third step of the method;

Fig. 4 is a view in axial section of the completely formed article constituting a pressure tank and with parts broken away to reduce its 50 height;

Fig. 5 is a horizontal sectional view taken on the line 5-5 of Fig. 4 looking downwardly as indicated by the arrows; and

Fig. 6 is a fragmentary view in vertical section 55 greatly enlarged and not necessarily in proper proportion.

Referring first to Fig. l of the drawings, there is shown a one piece, seamless mold shell ID including a cylindrical wall ll entirely opened at its lower end l2 and merging at its opposite end into awdome-like top wall I3, closing said end except for a collar receiving opening l4 positioned at its crown. A short tube l5, which constitutes a collar forming a part of the finished tank herein disclosed, is fitted in the opening l4 and projects for the major portion of its length above the wall l3. Fitted beneath and conforming to the wall I3 is a rugged, internal reinforcement for the mold comprising a shoulder IS, the upper portion of which is provided with a flat seat H on which tube or sleeve [5 rests. A blocking oif cap [8 of celluloid or other insulating material extends across the top of the collar I5 and is outlined by a depending flange l9 which extends downwardly around the collar for a short dis tance. The flange is of such depth and otherwise designed so as to permit the deposition of metal as hereinafter described on the lower portion of the collar while blocking off the upper portion from any such deposition.

The lower open end l2 of the mold shell I0 is closed by means of a blocking off plate 20 of insulating material and which includes an upstanding flange 2| surrounding the lower end of the cylindrical wall II and extending upwardly secured together by means of a tie rod 22 which extends axially through the construction, has one end 23 in screw threaded engagement with a boss 24 depending centrally from the top of the cap l8 and arranged so that the cap may be readily inserted on and unscrewed from the tie rod. The tie rod passes through and is secured to the shoulder l6 by a frictional tight fit therein and passes centrally and loosely through the blocking off plate 20. A nut 25 engaging the projecting end of the tie rod is disposed to bear on the blocking off plate and thus clamp the parts in the position shown in Fig. 1. It is a feature of this disclosure that the mold shell I0 outline the major portion of the configuration of the finished the wall l3. It is particularly desirable that this mold shell be free of joints, angles or other breaks and that it provide a continuous, smooth surface with the parts curving gradually one into another. In the instant case it is desired that the interior surface of the finished article be highly polished and accordingly the deposit receiving surface of the mold shell ID is given a high polish before being. subjected to use. It has been found that the character of the depositing receiving surface is much improved if it be formed of, or coated by, a layer of chromium and accordingly the mold shell I0 is herein shown to be plated on its deposit receiving surfaces with a layer 26 of electrolytically deposited chromium.

With the mold parts thus assembled the construction is subjected to the action of an electrolytic bath. In the instant case the assembly is subjected to the action of such a bath containing nickel until there is formed on the exposed part of the shell l0 and on collar I5 .an inner thin layer 21 of electrolytically deposited nickel.

The mold so plated is removed from the nickel bath and is then subjected to the action of an electrolytic bath containing copper until a layer 28 of copper is formed on the initial nickel layer. While it is obvious thatthese deposited layers may be of any desired thickness, in the instant case they are of the order of approximately 25 thousandths of an inch thick, so that the resultant tank shell 29 is about fifty thousandths of an inch thick.

With the shell thus formed, the nut 25 is looscried, the blocking ofi plate 20 slid downwardly and off of the mold shell, the blocking off cap I8 is unscrewed and a stripping ring 30 substituted in place of the blocking olf plate. Prior to stripping the shell from the mold, it is a preferable practice to quickly grind and polish the outer exposed surface of the copper layer 28. This treatment has two advantages, first it prepares the copper layer to receive the subsequent layer hereinafter described, and the incidental heat generated expands the shell suflicient to insure an easy slipping of the shell off the mold without distorting either the shell or the mold. It has also been noted that the presence of the'chromium layer 26 provides a slippery surface which assists in the easy removal of the shell 29. Holding the interior reinforcing parts by means of the tie rod 22, the stripping ring 30 is moved-upwardly as indicated by the arrows in Fig. 2, the ring 30 having a snug but sliding fit on the chromium coated shell Ill. Pressure exerted on the ring 20 as it is moved upwardly in Fig. 2 has the effect of stripping the shell 29 off the mold shell l0, carrying with it the collar [5 which has been electrolytically soldered to the shell by the upturned rim portion 3| of the shell. The shell 29 at this stage of the method and when removed from the remaining mold parts is as shown in upper portion of Fig. 3.

In tanks'of the character herein illustrated, it is usual to provide a bottom of a concaved type and accordingly there is illustrated in Fig. 3 a heavy, separate bottom preforming member 32, for closing the open bottom of the shell 29.: This member 32 is in the form of a flat disk having an upwardly curved, concaved portion 33 outlined by an upstanding flange 34 designed to have a snug fit on the open bottom end of shell 29. The bottom member 32 is forced into place until the open end 12 is telescoped fully into the flange 5 34, as shown in Fig. 4.

The present disclosure features the providing of a surface for receiving the outermost or facing coating which surface shall be free of joints, cracks, recesses, reentrant angles or other breaks in the desired continuity and smoothness of sur- 5 face required. Accordingly, the shoulder or annular re-entrant angle formed between the top of flange 34 and the adjacent side of layer 28 is filled with a solder 35 and this filler is ground to provide a smooth, curve 36 joining the side of the flange 34 with the side of the copper layer 28 thus eliminating any breaks in the exposed surface. 1

In the illustrated form of the invention herein disclosed, the bottom member 32 is a plate copper stamping but it is obviously Within the scope of the disclosure to make the member 32 as a stamping, a pressing or a casting, and it may be formed of nickel or a coating of nickel with its inner face polished to meet those situations where it is desired that the entire inner surface of the tank be outlined by a polished nickel surface.

The parts as thus prepared are ready for the finishing operation which consists in subjecting the same to the action of an electrolytic bath of the desired coating material. In the instant case, this bath is nickel and there is formed on the entire exposed surface a nickel layer 31. This layer will not be of uniform thickness at all its parts. The depositions will be less dense, that is, of reduced thickness on its concaved surfaces, than on its straight or slightly curved portion, as on the mold shell [0. The mid-portion 38 of the part which extends across the concaved portion of the bottom member 32 will be relatively thin, so that dependence has to be made primarily upon the member 32 itself to provide the requisite tensile strength to the bottom portion of the completed article. On the contrary, it has been found that the density of deposition, that is, the thickness of the deposited layer will be increased and of greatest thickness as it passes about the outer edge 39 of the member 32, than it is on the shell 29. Massing of deposits about the bottom of fiange 34 has the effect of providing a rather rugged ring 40 which provides structural strength to the bottom of the tank. In this way there is compensated any weakening effect in the tank at the point of juncture between the shell 29 and the bottom member 32. In this case, the entire exposed surface of the tank has the beautiful silvered appearance of electrolytically deposited nickel and the surface is continuous without there being visible from the outer side any joints or breaks in the continuity of the surface.

It is understood that the mold parts thus used will receive a quick polish on the exposed deposit receiving surface, a new collar IE will be as semblcd with the parts as indicated in Fig. 1, and the operation repeated. In due time,'it will be found that the thin chromium layer 26 will begin to show wear but can be restored to its original condition by being replated in a chromium bath until the desired surface is again attained, but it will not be necessary to replate the mold after each operation. The alternate layers of different character of deposited metal provides a structure of high tensile strength while economizing in weight and material used, it being necessary simply to supply additional weight of material to those parts, such as the concaved bottom, which do not lend themselves readily to the for-, mation of electrolytically deposited layers of the requisite tensile strength to correspond to the strength of layers formed on convexed in distinction from concaved surfaces. Tanks prepared in the manner herein suggested are par cularly desirable as containers for certain chemicals, such as containers for fire extinguishing liquids, which are more liable to attack the usual rough lined surfaces than highly polished surfaces, such as can be formed on the polished mold Hi herein featured.

I claim:

1. In the art of forming hollow metallic tanks, the method which consists in blocking off the end of a mold at that part which is to form the bottom end of the completed tank, subjecting the assembly to the action of an electrolytic bath to form on the exposed part of the mold a layer of electrolytically deposited metal constituting the major portion of the completed tank, except the bottom, removing the blocking off means, with-- drawing the mold from the portion of the tank thus formed through said bottom end, securing a preformed bottom to said major portion to complete the tank and subjecting the tank so formed to the action of an electrolytic bath to cover both said major portion and said preformed bottom with a single, integral coating layer of electrolytically deposited metal.

2. In the art of forming hollow cylindrical metallic tanks, the method which consists in subjecting a mold with blocking off means at the part which defines the bottom end of the completed tank, to the action of an electrolytic bath to form on the exposed part of the mold a layer of electrolytically deposited metal constituting. the major portion of the completed tank, except 10 the bottom, removing the blocking off means, withdrawing the mold from the portion of the tank thus formed through said bottom end and securing a preformed bottom to said major portion to complete the tank. 15

3. In the art of forming metal tanks of cylindrical form having concaved bottoms, the method which consists in providing a cylindrical open end shell of electrolytically deposited metal, with a preformed, metallic bottom forming memher having the concaved configuration required in the finished tank positioned at its open end, filling any breaks in the joint between the shell and member, polishing the exposed surfaces thereof to provide a smooth, continuous, deposit receiving surface across and between the shell and member, and subjecting the shell with its bottom forming member to the action of an electrolytic bath to provide a facing coating for the tank extending integrally across both the shell and the bottom forming member.

4. In the art of forming tanks, the method which consists in providing an open bottom of a shell formed primarily of electrolytically deposited metals and having a preformed closure at one end, filling with solder and smoothing out any reentrant angles or joints formed between the shell and said closure to thus provide with the shell and its closure a smooth deposit receiving surface, subjecting the same to the action 40 of an electrolytic bath to form a layer of metal on said shell and closure, extending across the solder filled angles and acting tosecure the closure to the shell.

'5. A mold for use in preparing hollow metallic articles by electrolytic deposition, comprising a plurality of separable parts including an integral seamless metallic shell including a cylindrical wall open at one end and a dome-like top wall provided at its crown with a collar opening and otherwise closing the other end, a collar fitted in said collar opening and protruding from the top wall, a blocking ofi cap fitting the protruding end of the collar and spaced from the top wall to expose part of the collar, a blocking off plate fitting about said open end of the shell to close the same, an internal reinforcement including a shoulder fitting the inner side of the dome-like top wall, and engaging the inner end of the collar, a tie rod with one end engaging the collar, passed through and engaging the shoulder, and passed through the blocking off plate and a nut in threaded engagement with the tierod and bearing on the blocking off plate to secure the said separable parts temporarily in position.

Gel-1 a device of the class described, the combination of a part of a mold for use in an electrolyt bath, comprising an integral shell including a'"cylindrical wall having one end open and 9.70 dome-like end wall partially closing the other end, said shell adapted to provide a receiving surface for a layer of electrolytically formed metal, and a stripping ring snugly but slidably fitting about the cylindrical wall at the open end of the shell and adapted to bear on the layer to strip the same off the mold.

7. In a device of the class described, the combination of a mold including a cylindrical part and an internal reinforcement therefore, a portion of said cylindrical part adapted to receive a shell formed of laminations of electrolytically deposited metals and means for removing the mold and its internal reinforcement from the shell, said means including a stripping ring snugly but slidably fitting said mold and adapted to bear on the adjacent edge of the shell to slide the same off the mold.

8. In a device of the class described, the combination of a mold including a cylindrical part, providing a ring receiving portion, and a portion adapted to receive a shell formed of laminations of electrolytically deposited metals and a stripping ring snugly but slidably fitting said ring receiving portion of the mold and adapted to bear on the adjacent edge of the shell to slide the same of! the mold.

9. A mold for use in preparing hollow metallic articles by electrolytic deposition, comprising a plurality of separable parts including a metallic shell having a cylindrical wall open at one end, and a dome-like top wall having an opening at its crown portion, a blocking off cap at the crown of the top wall closing said opening, a blocking off plate telescoping the open end of the shell to close the same, an internal reinforcement including a shoulder fitting the inner side of the dome-like top wall, a tie rod passed through and engaging the shoulder and connecting the blocking ofi cap and plate and securing the same to the shell.

10. A mold for use in preparing hollow cylindrical articles by electrolytic deposition, comprising a plurality of separable parts including a metallic shell having a cylindrical wall open at one end and a wall at the other end, a blocking 5 off plate closing the open end, an internal reinforcement including a shoulder engaging the end wall and removable as a unit through the open end and a tie rod connecting the blocking off plate and the shoulder.

11. A mold for use in preparing hollow metallic articles by electrolytic deposition, comprising a plurality of separable parts including an integral seamless metallic shell including a cylindrical wall open at one end and a dome-like top wall provided at its crown with a collar opening and otherwise closing the other end, a collar fitted in said collar opening'and protruding from the top wall, a blocking ofi cap fitting the protruding end of the collar and spaced from the top wall to expose part of the collar, an internal reinforcement including a shoulder fitting the inner side of the dome-like top wall, and engaging the inner end of the collar and adapted to be withdrawn from the shell through said open end. 12. In a mold construction the combination of a tie rod, a blocking of! cap in threaded engagement with one end of the rod, a shell reinforcement secured to the red, a blocking ofi plate loose on the rod adjacent the other end of the rod and in spaced relation to the cap and reinforcement and a nut threaded to the rod and adapted to bear on the plate to'force the same towards the cap and reinforcement.

BLASIUS BART. 

